"This is an individual who's running as a fiscal conservative but the fact is that he voted eight times to raise the debt ceiling in Washington, D.C.," Perry said on Fox News. "He's an earmark king, if you will."
"So please don't stand up here in Iowa and tell me what a great fiscal conservative you are when your record doesn't hold up to your type of scrutiny," the Texas governor added.
Perry has been pounding Santorum's congressional record in recent days as the former senator from Pennsylvania has surged in the polls. He's called Santorum a "prolific earmarker" and released a Web ad Monday describing Santorum as a "porker's best friend."
The two men are competing for the same group of conservative caucus voters who want to see cuts in government spending.
Santorum is in a virtual tie with Mitt Romney and Ron Paul in the early-voting state, while polls show Perry in fifth place. The Iowa caucuses take place Tuesday evening.